1. Field
The present invention relates to an organic light emitting diode display device and a method for driving the same.
2. Related Art
In accordance with the advancement of an information-oriented society, a demand for a displaying device for displaying an image has increased in various types. Accordingly, a flat panel display (FPD) device such as a liquid crystal display (LCD), a plasma display panel (PDP), or an organic light emitting diode (OLED) has been recently used. Among these flat panel display devices, the OLED is driven at a low voltage and has a thin type, an excellent viewing angle, and a fast response speed.
The OLED includes a plurality of pixels arranged in a matrix form. Each pixel includes a scan thin film transistor (TFT) supplying a data voltage to a data line in response to a scan signal from a scan line and a driving TFT controlling an amount of current that is supplied to the OLED according to the data voltage supplied to a gate electrode. In detail, the driving TFT controls the amount of current flowing in the OLED from a high potential voltage supplied to the each of the pixels, thereby making it possible to control an amount of emission of the OLED.
Recently, each of the pixels of the OLED display device includes a white subpixel in addition to a red subpixel, a green subpixel, and a blue subpixel. In case of the white subpixel, since the color filter is not required, the white subpixel has a higher transmissivity than the red subpixel, the green subpixel, and the blue subpixel. Therefore, the OLED display device including the white subpixel may reduce a red light, a green light, and a blue light output from the red subpixel, the green subpixel, and the blue subpixel, respectively, due to a white light output from the white subpixel, thereby making it possible to significantly reduce power consumption.
However, when the OLED display device including the white subpixel displays a digital video data for a low gray scale region, even if the white light is finely adjusted, a color distortion is easily generated due to an intensity of the white light output from the white subpixel. As a result, the OLED display device including the white subpixel has a difficulty in uniformly maintaining a color temperature for all gray scale. When the digital video data of 8 bits is input to the OLED display device, the gray scale may be represented by a value ranging from 0 to 255. In this case, the low gray scale region indicates a black gray scale region having a value ranging from 0 to 63.